Model versions

Efforts from the Cornell group and collaborators have led to the development of CNCPS v7, creating new, and revising current, predictions for nutrient flows and animal requirements. Major updates to the current platform include: 

• Temporal representation of nutrient flows throughout the gastrointestinal tract based on user described meals for the animal modeled. Results will provide maximum and minimum rates and concentrations of nutrients, given users a better indication of nutrient status for the animal modeled. 

• Representation of the complete gastrointestinal tract allows for estimation of total tract digestibility of ingredients fed. 

• Disaggregation of the integrated fiber degradation rate for forage ingredients, creating separate ‘fast’ and ‘slow’ fiber pools, each with their own rate of degradation. This revision looks to promote improved resolution of fiber digestibility in the rumen and energetic status in the animal. 

• Inclusion of protozoal metabolism and nutrient composition in the rumen submodel to better represent microbial nutrient flow, with particular emphasis on amino acids. 

• Inclusion of endogenous nitrogen supply, and subsequent demands, along the gastrointestinal tract to properly account for nitrogen status in the ruminant. An updated equation for nitrogen recycling has been included. 

• Consideration of alternative measurements for intestinal digestibility of nitrogen in non-forage, low fiber ingredients which are ill-represented by the detergent system (i.e., neutral detergent insoluble nitrogen (NDIN) and acid detergent insoluble nitrogen (ADIN)).  

• Updated, variable efficiencies of use for essential amino acids toward maintenance and other productive purposes. 

Version 7 resources:

• The Cornell Net Carbohydrate and Protein System version 7: What is Taking So Long? - Drs. Mike VanAmburgh and Andrew LaPierre  

• CNCPS v7 overview slide set – Dr. Andrew LaPierre